fix: reset page data on 404 (#497)

src/client/app/router.ts

@@ -123,6 +123,15 @@ export function createRouter(
         latestPendingPath = null
         route.path = pendingPath
         route.component = fallbackComponent ? markRaw(fallbackComponent) : null
+        // reset page data
+        route.data = {
+          relativePath: '',
+          title: '404',
+          description: 'Not Found',
+          headers: [],
+          frontmatter: {},
+          lastUpdated: 0
+        }
       }
     }
   }

src/client/theme-default/components/LastUpdated.vue

@@ -7,7 +7,7 @@ const { theme, page } = useData()
 const hasLastUpdated = computed(() => {
   const lu = theme.value.lastUpdated
 
-  return lu !== undefined && lu !== false
+  return lu !== undefined && lu !== false && page.value.lastUpdated !== 0
 })
 
 const prefix = computed(() => {